King.com, a UK-based game developer that has been on Facebook for all of a year and a half, is now the second largest on the social network in terms of daily players with 10.4 million. Veteran games publisher EA, on the other hand, now sits in fourth place by that measure behind Wooga with just over 9 million. And King.com doesn't look to stop there.

"Our ultimate ambition is to be the leader in our segment of games for the casual social player, mainly female, social and mobile," King.com CEO and co-founder Riccardo Zacconi told Reuters. "Our target is to reach Zynga."

Keep in mind that Zynga has been around for nearly five years and is home to 65.3 million daily players, more than triple the next three game makers behind it combined. When we spoke with King.com CMO Alex Dale recently as the game creator beat out Wooga in daily players, he chalked the wild success up to iteration and targeting the right audience. In this case, King.com simply took its most popular casual games and made them social.

After just recently seeing Candy Crush Saga debut on Facebook, King.com has its sights on two things for the future: mobile gaming and an initial public offering, according to Reuters. Europe's biggest social games maker might have the world's biggest in sights, but it looks like Zynga is already prepared for an assault.